Such automatic biochemical analyzers for analyzing biological samples have been known, as proposed in Japanese Patent Laid-Open No. 2024/1993. In this prior art technique, a plurality of sample containers are set on a sample disk. In this instrument, aliquots of sample in the sample containers set on the sample disk are drawn in by a sample pipette and dispensed into reaction containers on a reaction disk. A reagent pipette draws in reagents from plural reagent disks and adds the reagents to the aliquots of sample. Thus, the sample is analyzed in terms of plural items. During the analysis, the order in which the items are analyzed is determined, taking account of the time required for the processing, in order to shorten this processing time.
In this automatic biochemical analyzer, plural kinds (e.g., four kinds) of reagents are successively added to a biological sample in each reaction container on the reaction turntable. The induced reactions are optically detected. The added reagents are referred to first through fourth reagents, respectively, according to the order in which they are added. Whenever each kind of reagent is put into a reaction container, it is necessary to stir the mixture inside the container.
Providing a reagent pipette and a stirring device for each different kind of reagent may also be conceivable. That is, four sets of reagent pipettes and stirring devices corresponding to the first through fourth reagents are arranged around the reaction turntable. However, the sample pipette for pipetting the sample into the reaction containers, a washing device for washing the sample pipette, a detector, a washing device for washing the reaction containers, and so on are disposed around the reaction turntable. Therefore, limitations are imposed on the space where those reagent pipettes and stirring devices are installed. Consequently, it is very difficult to dispose as many as four sets of reagent pipettes and stirring devices around the reaction turntable.